<style type="text/css">
  *{
    font-family:'Helvetica', sans-serif;
  }
  iframe{
    border:1px solid #ddd;
  }

  .group{
    border-bottom:1px dotted #ccc;
    padding-bottom:25px;
  }
</style>

<div class="iphone4 group">
  <h2>iPhone 4</h2>
  <iframe width="320" frameborder="0" height="480" src="."></iframe>
</div>

<div class="iphone5 group">
  <h2>iPhone 5</h2>
  <iframe width="640" frameborder="0" height="1136" src="."></iframe>
</div>

<div class="ipadmini group">
  <h2>iPad Mini</h2>
  <iframe width="768" frameborder="0" height="1024" src="."></iframe>
</div>
